The University of Pennsylvania (UP) is a member of the Radiation Therapy Oncology Group (RTOG). It participates actively in RTOG affairs. It not only contributes large numbers of patients, especially those with head and neck tumors, but non-radiation therapy specialists contribute both time and effort in committee work and in providing consultative services. Dr. James Snow, Chairman of the Department of Otorhinolaryngology, and Dr. John Glick of the Medical Oncology staff are members of the Executive Committee. Dr. Glick serves on the writing committee for lymphoma studies, and Dr. Snow as a member of the Head and Neck Field Committee. Dr. John Mikuta is an active collaborator in RTOG studies related to gynecologic oncology. Thus, the University of Pennsylvania exemplifies in its activities a committment to the interdisciplinary approach to patients with oncological diseases. UP therefore assists RTOG, a cooperative group of radiation therapy research and clinical centers, in the conduct of joint clinical investigation. The group conducts randomized clinical trials and other cooperative clinical studies in an endeavour to advance knowledge in the cure and control of cancer. Through the collaboration of its members, RTOG is able to accumulate numbers of patients necessary for the answer to important questions utilizing the randomized clinical trial approach. It also makes possible the collection of long-term data with regard to radiation complications and patient survival, and promotes multi-disciplinary care by integrating its study programs with those of other disciplines. In that way it also enriches training programs in oncology as well as radiation therapy.